Posted By: 68notch
best shift point ? - 12/29/10 01:23 AM
68 barracuca , 71 440 , 9.5 keith black , 509 purple , dual 4 wieland tunnel ram , 625 carters , 4 speed , 3.91 sure grip , msd 6 , 2 inch hooker fenderwell headers , 3 1/2 inch glasspacks , i am thinking 6000 for banging gears , too much for the stock bottom end ? or am i being parriniod , or should i let it wind to 7 ?
I would think ideally, yeah...6500 is the minimum that it would like. What kind of heads? What work has been done?
6500 should be okay for a stock bottom end...
Posted By: dennismopar73
Re: best shift point ? - 12/29/10 03:27 AM
6500 i dont shift my race car there
hell shift it at 7500 let er fly
hahah
can help but hink that ?? 5500 is really pushing it
Posted By: Sport440
Re: best shift point ? - 12/29/10 03:48 AM
While, that combo could still easily rev to 7000 rpm, Id keep it around 6000-6200 rpm for best ET and engine longjevity.
You wont get to many passes reving it to 7000 grand
Posted By: Sport440
Re: best shift point ? - 12/29/10 04:16 AM
With those heads and cam 6000 rpm will be plenty.
With free flowing heads the 509 cam is done around 6200 rpm, but will rev higher. mike
Posted By: 383man
Re: best shift point ? - 12/29/10 05:38 AM
I like to shift by the feel of the eng. When it seems to peak I shift. I can tell you I have a mild 906 headed 440 in my 63 right now with the MP .557 cam. It feels like 6200 is the happy spot. Thats where I shift it at and it traps about 6300 to 6400. Ron
Posted By: 68notch
Re: best shift point ? - 12/29/10 06:04 AM
thanks very much , another question if i may , if im going for better heads in the future , should i think about beefing up the bottom first ?
Yes, Yes, & Yes. If it breaks, it's liable to take a lot of parts with it. If a rod lets loose @ 6k, you could easily find yourself salvaging only the headers and intake..... literally. Build the foundation before you start on the second story.
Posted By: DaytonaTurbo
Re: best shift point ? - 12/29/10 09:27 AM
I'd push it to 6000. With those stock heads I don't think there'd be any gain to taking it higher.
Posted By: Anonymous
Post deleted by moparts - 12/29/10 05:01 PM
Posted By: pressureangle
Re: best shift point ? - 12/29/10 05:34 PM
Stock heads aren't the best combo to put under a tunnel ram and 2" headers. My WAG is that about 6k will be your shift point, but it may be 500 RPM either side of that. Let your time slips be your guide. 60ft time will give your best launch RPM, and 1/4 mile MPH will give best shift RPM.
If the motor has no modifications to the oiling system, RPM over 5500 risks starving the rod bearings.
Posted By: Mr.Yuck
Re: best shift point ? - 12/29/10 07:00 PM
Shift where you feel it's best. With stock heads I'd guess you'll be maxed out around 6000-6200. I had a 509'd 383 w/ ported 915 2.14/1.81 valves. Friend asks what are you shifting at? I said 6800, he's like whooo dude whay to high try 62-6500. did and it slowed the car down. Drive it you'll know where the power drops off. I pulled 3rd one time at 7200, helped me win by a 1/2 fender against at Chevy II in the finals.
Posted By: sixpackgut
Re: best shift point ? - 12/29/10 09:58 PM
old timer would jump in some guys 440 powered car and shift at 5500 and get a new best in the other guys car. over and over this would happen. i heard him tell this story so i tried it, my car was a 493 but i was spinning around 6500. ET didnt change much but my mph went up shifting at 5800.
about a year ago, in the race section, a guy got a new best with a 440 shifting it at 5200. most guys would never even try that so they would never find out
Posted By: RTDaddy
Re: best shift point ? - 12/29/10 10:23 PM
Carowner: "How do you know when to shift?"
Reply: "When it feels like the floorboards getting ready to lift"
You can usually feel the car start to nose over, it's time.
"IF YOU'RE UNDER CONTROL, YOU AIN'T GOING FAST ENOUGH."
Posted By: DaveRS23
Re: best shift point ? - 12/30/10 02:31 AM
My personal experience with more or less stock bottom ends has been that a 6,000 RPM shift point is kinda the dividing line. The farther under 6,000 I keep them, the less troubles I have. The more often that I approach and pass 6,000, the problems come more often.
And on my engines, the power drops off fast in the high 5,000s with stockish heads.